Curling tongs



A. REHM ET AL CURLING TONGS March 15, 1932.

Filed April 19, 1929 Patented Mar. 15, 1932 UNITED STATES- ALIBED REE]! AN D EDGAR SACHS, OF STU'ITGABT, GERMANY, ASSIGNOBS TO BOFERT PATENT OFFICE I BOSCH .AKTIENGESELLSCHAFT, OF STUTTGABT, GERMANY CUBLING TONGS Application m April 19, 1929, Serial :0.

a heating element and insulating means for said element which will produce aminimum temperature drop.

To obtain this object a heating element is according to the invention, inserted in a glass tube having at least one-U-bend therein.

Glass, similarly to any electrical insulator, is a poor thermal conductor, but allows radiating heat to pass through. Consequently even when its outer wall is at a comparatively high temperature the inner wall of the glass tube is still far below its melting point.

Two forms of construction of the invention are shown by way of' example in the drawings in which Figure l is a view ofai heating element, partly in section.

Figure 2 is a cross-section on a larger scale through a round curling tong arm with a heating element as shown in Figure 1 inserted therein. Figure 3 is a cross-section on a larger scale through a crescent-shaped. curling tong arm with a heating element asshown in Figure 1 inserted therein.

Figure 4 is aview of the second form of heating element and Figure 5 is a cross-section on a large scale through a double curved heating tong arm with a resistanceas shown in Figure 4 inserted therein.

In the construction shown in Figure 1-3 an electrical heating wire 2 is inserted in a U- shaped tube 1 of ordinary glass. The two ends of the arm of the glass tube are sealed by a common glass seal 3 in which thetwo leads 4 to the heating wire 2 are fused. The surface, of the glass seal 3 at which the two 856,425, and it Germany October 6.1928;

wires 4 emerge is provided with two extensions or mountin elements 5 over which an insulating tube not shown) can be placed to protect the wires 4. The glass tube 1 may be fitted into a roun sheet metal sleeve 6 (Figure'2) or into a crescent-shaped sheet metal sleeve 7 (Figure.

3) and is secured therein by cement 8 made from graphite and'water-glass with addition of water. This cement is ,a "good conductor of heat and adheres well to glass and sheet metal without attacking the same. The sleeves 6 and 7 are inserted in suitable hollow arms 9 and 10 of curling tongs. The mechanical strength of the heating element is increased by the insertion in the sheet metal sleeve and is thereby at the same time given a definite shape which facilitates replacement.

In producing the heating element the helically wound heating wire 2 is first inserted,

with the two wires soldered to it, in a glass 1 tube at least approximately straight, the melting point of which is below the melting point of the heating wire. The glass tube is then heated at its centre and bent into the U- shape. The glass element 3 is then fused on to the open end of the glass tube and the two wires 4 nipped it so as to form the two extensions 5.

)If desired the glass tube may also be bent into a multiple U. A sinuous glass tube 11 is shown in Fig. 4. Instead of cementing the glass tube in its sheath, it can also be cast in with a substance having high thermal con ductivity. In the form of construction shown in Fig. 5 the glass tube 11 of difiicultly fusible glass is cast-in with aluminum 12 and the casting is inserted in a double curved hollow curling-tong arm13: Aluminum is a good conductor of heat and can easily be cast in any desired shape. If desired the casting eluding a hollow tong element, a lug similar in cross-sectional shape to the s ape of the tong element .located within said tong element, a glass tube having at least one U-bend ing-tong arm so that the sheath or sleeve ele- I 1. Au electrically heated curling tong intherein within said tong element and secured in the material of said plug, a heating wire within said glass tube and projecting beyond the ends thereof, and sealing means at each end of said glass tube.

V 2. An electrically heated curling tong in cluding a hollow tong element, a sleeve within said tong element, filling material embedded in said sleeve to for a plug, a glass tube having at least one U end therein within said tong element and secured in said filling ma terial, a heatin wire within saidglass tube and projecting eyond the ends thereof, and sealin means at each end of said glass tube.

3. n electrically heated curling tong inp cludin a hollow tong element, a sleeve within sai tong, cementof high thermal conductivity embedded in said sleeve to form a plug, a'glass tube having at least one U-bend therein within said ton element and secured in said cement, a heat ng wire within said glass tube and projecting beyond the ends thereof, and sealing means at each end of said glass tube. v

4. An electrically heated curling tong including a hollow tong element, a sleeve within said tong, cement formed of graphite, wa-

ter glass and water embedded in said sleeve to form a plug, a glass tube having at least one U-bend therein within said tong element and secured in said cement, a heating wire within said glass tube and projecting beyond the ends thereof, and sealing means at each end of I said lass tube.

5. n electrically heated curling tong including a hollow tong element, a lug similar in crosssectional shape to the s ape of the tong element located within said tong element, a glass tube-having at least one U-bend therein within said tong element and secured in the material of said plug, a coiled heating wire within saidglass tube and projecting beyond the ends thereof, and sealing means at each end of said glass tube.

6. An electrically heated curling tong in-- cluding a metal ton element, a glass tube having at least one. U- end therein within said tong element and a heating wire within said glass tube and-projectingv beyond the ends thereof.

In testimony whereof we havehereunto affixed our signatures.

. t ALFRED REHM. EDGAR SACHS. 

